A Philippines protest got out of hand as a police van rammed protesters outside of the American Embassy in Manila.

The incident took place Wednesday as violence erupted during an anti-U.S. rally, sending at least three student activists to the hospital after they were run over by the police van, protest leader Renato Reyes told The Associated Press.

“There was absolutely no justification for it,” Reyes said when commenting on the dispersion of 1,000 or more Philippine protesters, according to the AP. “Even as the president vowed an independent foreign policy, Philippine police forces still act as running dogs of the U.S.”

“18 indigenous people and a member of the media were arrested,” Reyes added.

Police Officer Franklin Kho, who was driving the police van, claimed that protesters were trying to flip the vehicle over, which prompted him to get in the van and drive it, ABC News reported.

The national police called the incident “unfortunate” in a statement and said that there will be an investigation to determine if police followed crowd-control procedures, ABC News noted. Police added that investigators will also look into the actions on part of the protesters to determine if any crimes or civil liabilities were committed during the protest.

Despite the fact that the Philippines has had a longtime alliance with the U.S., protesters gathered outside of the embassy on Wednesday, demanding that U.S. troops leave the Philippines and give support to their president, Rodrigo Duterte, who’s now pushing a foreign policy that doesn’t require a dependence on the U.S., USA Today reported.